The invention provides a particle therapy system in which whether to perform any one irradiation method of a raster scanning method and a discrete spot scanning method can also be selected based on previous selection depending on a target volume 41 of a patient 4 to be irradiated, and either of the irradiation methods of the raster scanning method and the discrete spot scanning method is configured to be capable of being performed by one irradiation apparatus 500. Therefore, a small particle therapy system capable of achieving both higher accuracy irradiation and high dose rate improvement is provided.